The number of people having their stomach stapled and other weight-loss operations on the NHS has risen by more than half in the last year, new figures show.

Television presenters Anne Diamond and Fern Britton are among those who have admitted that the surgery helped them to lose excess weight.

There was a 52 per cent rise in the number of the obesity operations carried out by the health service between May 2008 and April this year, new figures show.

Overall there were 4,324 such operations carried out in the 12 months to April, up from 2,838 the previous year, according to the figures published by the NHS Information Centre.

Three quarters of the procedures, which can cost up to £12,000, were carried out on women.

Under new guidelines published by the National Institute for Health and Clinical Excellence (Nice) in late 2006 surgery can be considered a first line treatment for patients with a Body Mass Index (BMI) of more than 50.

Studies have suggested that they can help improve conditions triggered by obesity, such as diabetes.

One in four Britons is now considered obese, with a BMI higher than 30.

Tam Fry, from the National Obesity Forum, said that the rise in the number of operations could be "hugely detrimental" to the NHS.

"Gastric surgery is a last ditch resort," he said.

"We should concentrate on lifestyle change and using weight loss drugs."

He added: "In the long term, these operations may benefit the NHS because people may not get diabetes or heart attacks, but we have to pay for them in the short term, which is a huge problem."

BMI is a ratio of weight in comparison to height.

A person's score is calculated by dividing their weight in kilograms by their height in metres squared.

A BMI of between 18 and 25 is considered normal, 25 to 30 overweight, 30 to 40 obese and over 40 morbidly obese.

The NHS Information Centre, which published the figures, also found the number of people with stab wounds being treated in hospital dropped by almost four per cent over the same period.

Mr Fry added: "I don't think there is any evidence that women are more likely to be obese.

"But they are more likely to go to their doctor and get these things sorted out.

"This is a long seen phenomenon.

"Women are much more likely to go to their GP at the drop of a hat, while GPs have forgotten many of their male patients names, so little do they see them.

"Men are much more inclined to shrug and say so be it, and also to refuse to believe that they will develop conditions like Type 2 diabetes."

More than two million people in Britain suffer from diabetes, and cases are expected to spiral in coming decades in part because of lifestyle issues and the growing obesity crisis.

Between 2006 and 2007 there were just 1,951 treatments categorised as bariatric surgery, the umbrella term for weight loss surgery, which can include range of methods, including inflating a balloon inside the stomach, placing a band around the top and stapling a portion of it shut.

While one in four Britons are obese another 37 per cent are overweight, official figures show.

Just 38 per cent of the adult population of England is a healthy weight, according to the figures.